Resetting NiCad Batteries

I have an older cordless drill and the battery seems to be dead. Yeah I know I could just buy a new one, but I have heard you can re-set the battery using a normal car battery charger. I read the procedure online and tried it. It did seem to revive the battery but it still doesn't seem to want to charge in the normal charger.

I checked the charger and it seems to be putting out enough voltage to charge the battery. The battery also seems to be taking a bit of a charge when I use the car battery charger.

Not a big deal, but this has me curios now about why it won't charge when I put the battery in the charger.

Yep, I also cleaned all the contacts and applied Stabilant to them.

 

Well for anyone interested in this I did some more research and apparently the "re-setting" trick needs to be done on each cell. I started taking mine apart and may dig into more if I have time, but I'd basically have to take the whole thing apart and "reset" all nine cells then try it again. Looks like I've got at least two dead ones just by poking around quickly.

 

I've seen the suggestion about using a mig welder too. I think the battery charger would work just fine but I'd have to take the pack all apart and do it to every cell. Then I'd have to figure out how to put it all back together and get it working again.